body{
  display: table;
}
.div{
  display: table-cell;
  vertical-align:middle;
  width:400px;
  height: 200px;
  background: #ccc;
  overflow:hidden;
}

.bc{
  margin-left: auto;
  margin-right: auto;
}

.left-t , .right-b{
  position: absolute;
  width: 100px;
  height: 100px;
  background-color: #fc0;
  border-radius:50px;
}
.left-t{
  left: -50px;
  top:-50px;
}
.right-b{
  right: -50px;
  bottom: -50px;
}